Cut-out for electric circuits



(No Model.) 2 Sheets-Sheet 1.

E. THOMSON & E. W. RICE.

GUT-OUT FOR ELECTRIC GIRGUITSi N0. 320,017. Patented June 16, 1885.

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(No Model.) 2 Sheets-Sheet 2.

E. THOMSON & E. W. RICE.

CUT-OUT FOR ELECTRIC CIRCUITS.

Patented June 16, 1885.

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UNITED STATES PATENT OFFICE ELIHU THOMSON AND E. \VILBUR RICE, OF NEIV BRITAIN, CONN, ASSIGN- ORS TO THE THOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

CUT-OUT FOR ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 320,017, dated June 16, 1885.

Application iiled December 18, 1883. (No model.)

To aZZ whom it may concern:

Be it known that we, ELIHU THOMSON and E. VVTLBUE RIoE, citizens of the United States, and residents of New Britain, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Cut-Outs for Electric Circuits, of which the following is a specification.

Our invention relates to that class of cut- IO offs termed absolute cut-offs, whose object is first to shunt the current from that portion of the circuit containing the lamp, motor, or resistance which it is desired to cut out, and then to separate completely both ends of such portion of the circuit from the main circuit.

The object of our invention is, mainly, to reduce the cost of construction of such cut-outs and toincrease their certainty of action, their durability, and convenience of handling. IVe

v2Q attain these results by constructing our cutout of few parts, and these either cheap castings or punched metal; by a peculiar construc tion of the contact-springs and cam,which are kept clean and bright by friction and held 2 firmly by springs, and by constructing the box so that the works are easily removed to con nect up or adjust, and as easily replaced in position.

Figure 1 is a perspective view of the cut-out 3O mechanism and its box complete, with the connections to the main circuit and also to that portion (in this case symbolized by E E, indicating the carbons of an arc lamp) of the circuit which is to be thrown on or off. Fig. 2

is a similar view, except that the cut-out mechanism is here shown partially separated from its cover B. Fig. 3 is an elevation of the mechanism with the cover completely removed and the parts in the position which al- 0 lows the current to flow through E E, or what is termec on circuit. Fig. 4- is a similar view when the parts are in position to cut off the current from E E, or off. Fig. 5 is a side elevation of the same. Figs. 6 to 15 show carries the operating mechanism of the cut-- out. This case is held in position by the screws 71 e, which pass into the laterally-pro jecting portion z of the board F when the case is in place. The case or cover 13 has an opening, 0, closed by glass, so as to enable the chief contact-points to be seen from the outside. The wires marked 0 0 connect with some source of electric energy, and the wires L L are connected to any device for utilizing this currentas a lamp, motor, resistance,&c. A handle, H, projects from the bottom of the box, which, when turned in one direction, throws the current into E E, and in the opposite direction throws it 'oii' completely. The words On and Off are printed on the box in some suitable place, so as to enable one to see at a glance whether the current is on or off.

In Fig. 2 we have shown the method of arranging the cut-ont whereby the box or cover B B may be readily removed. The cut-out mechanism in our invention is mounted 011 a separate piece, F F, together with all the wires, attachments to circuit, &c. This flat piece F F is constructed with a right angle or lateral extension, 4;, at the bottom, which serves to hold the handle H, and forms the bottom of the boxB when slid into position. The screws 1) o serve to hold the frame F F and the case B B together, as before stated. This mode of construction cheapens the total cost, and also greatly increases the facility and ease of operation.

Fig. 3 shows all of the working mechanism of our cutout. F F is a flat piece of some suitable material, as wood or rubber, which serves as a support for the different parts of the cut-out. A A are two right-angle levers, of brass or some conducting material, sup ported and adapted to turn on the pillars or studs on blocks P P, and in electrical connection with said blocks, which blocks also serve as terminals and binding-posts for the circuit C C, as shown. To the short arms of the levers A A are connected springs S S, or equivalent devices, which tend to throw the long arms together. The long arms of AAare,

however, in the position shown held against the sheet-metal springs or contacts T T, which are turned up at their ends, so as to also serve as stops, preventing A A from moving far enough to strike each other or the cam X. The metal strips T T are so bent as to press firmly against the bottom of the levers A A, so that the latter will form a firm sliding contact with them. The strips T T are fastened to and in electrical connection with blocks or pieces \V W, which at the same time form or carry binding-posts for the terminals of the local circuit-Wires L L. Between the levers A Ais a short-circuiting arm or cam, X, supported on a pillar or stud rising from the block Z, and adapted to be turned in some suitable manner, as, say, by the handle H. XVhen in the vertical position, this cam is insulated and perfectly free from contact with any portion of the circuit, but on being rotated from this position will first form a short circuit by bearing upon and connecting the levers A A, and then lift the ends of the levers A A from any connection with the springs T T, thus opencircuiting L L. The spring Y has one end fastened to a pin, N, and the other end to the cam X in such a manner as to hold the cam X in either of its extreme positions, tending in this case, as the parts are shown in Fig. 3, to hold the cam vertical.

In Fig. 4 we have represented the (am X rotated about one-quarter of a revolution. In this position it will be seen that the arms of the levers A A are swung completely free of and electrically separated from both ends of the springs T T and circuit L L. The cam X is held firmly in this position by the pressure of the levers A A against its flat sides, and also by the spring Y, as shown, which now exerts its force on the opposite side of the center to that shown in Fig. 3. Suitable stoppins, t I, placed in the path of lever II, serve to limit the movements of said lever and the cam X.

Fig. 5 is a side elevation of the mechanism, showing that portion of the levers A A, cam X, and springs T T where the contacts occur.

Figs. 6,7, 8, 9, 10, 11,12, 13, and 14 are separate and detail views of the different parts, showing how they are constructed, the pieces P I? being similar, as are also the levers A A, (Figs. 8 and 9,) blocks IV and W, springs T and T.

Fig. 14 is a detail view of the shortcircuit ing cam or block X.

Fig. 15 shows the block Z and pillar, which act as a support for the cam X. e prefer to construct our cut-out in the manner indicated*that is, with similar interchangeable parts as the cost is thereby greatly reduced, and greater simplicity is secured.

The operation of our-invention is as follows: In the position shown in Fig. 3 the current from the generator or source of electricity e11- ters through the wire and flows, as shown by the arrows. through lever A, spring T, post \V, wire L to the apparatus E F, then returning through L to IV, to spring T, up leverA to P, and then through wire 0 to generator. The apparatus E E is thus connected in the same circuit with the generator, and has the current thereof flowing through it.

If now it be desired to cut off the circuit L E E L from any connection with the main circuit C C, the cam X is rotated by, say, the

handle H. Upon first contact of the cam X with the levers A A the current will then pass from A to A through said cam, thus shunting the main portion of the current from L L. A portion of the current, ofcourse, still flows in the circuit L L" inversely proportionate to the resistances of the two circuits, and the circuit L L is still charged to the potential of the main circuit. Upon further movement of the cam X, however, the ends of the levers A A are completelyseparated from any electrical connection whatever with the springs or terminals T T. The entire current now passes from A to A through the .cam X. It is manifestly desirablethat the cam X should remain in either of two positions-that is, either vertical or horizontal, completely "011 or off-and not be able to get into an inter mediate position, as described above, when the lights or apparatus in the circuit L L should be shunted from and yet in electrical connection with the main circuit. The spring Y serves to hold the cam in either of these ex treme positions, as before explained.

Fig. 5, which is a side elevation of our mechanism, shows that the parts are mounted so as to be in a plane removed from the surface of F, so that the points of contact between the cam X, levers A A, and springs T T are surrounded by free air-space. Great trouble in cut-outs constructed without this improve ment is often experienced, due to shortencuiting and burning out of the adjacent insulation. the local circuit L L be open when switched on. The are drawn under those conditions is almost certain to burn and destroy any insulating substance near it.

By constructing our cut-ont so as to have these contacts occur in free air between metal surfaces this difficulty is greatly lessened.

Having described our invention, what we desire to claim as new is 1. In an electric cut-out apparatus, the combination of the two line-contact levers or springs A A, the two contact block or points upon which said levers or springs normally rest, a local circuit connected to the contact blocks or points and containing the appa atus to be operated by the electric current, and an intermediate pivoted connecting cam-piece placed between the contact levers or springs, and normally out of contact with the same, but adapted to be turned so as to move both levers simultaneously in opposite directions, so as to cut out the apparatus in the local circuit, while at the same time completing the circuit between them directly.

2. The combination of the elbow cont-aetlevers, contact springs or steps for the same, forming the terminals of a local working-oil cuit, and a cam-plate, X, located between the This is especially liable to occur if ICO levers for operating the same and simultaneously forming a direct connection between them when the connection to the local working-circuit is broken.

3. The combination, with the elbow contact-1evers, of the intermediate conducting cam-plate, X, for forcing thelevers apart, said plate being adapted to form a direct connec tion between said levers when by the operation of the latter the connection between the line and the local working-circuit is broken.

4. In an electric cutout apparatus, the combination, with two contact-levers normally resting against contacts forming terminals of a local circuit and a short-circuiting and operating pivoted cam, of a spring or other device applied in the manner described, so as to act upon the cam on either side of its pivotal point and to hold said cam in either of its extreme positions.

5. The combination, with the contact-levers normally resting against two contact springs forming terminals for the local circuit, of the intermediate cam-plate, X, and the spring Y, applied to said plate in the manner described, so as to hold it in either of its extreme positions.

6. In an electric cut-out apparatus the combination of the conducting-blocks P P, the main-circuit wires clamped thereto, the coutact-levers mounted on said blocks, an intermediate cam-plate, the conducting-blocks \V V, local working-circuit wires clamped there to, and comlnctingsprings attached to said blocks and having their free ends projected into the path of the contact-levers, as and for the purpose described.

7. The combination, in an electric cut-out apparatus, of two pivoted contact-levers connected to the main circuit, an intermediate cam-plate adapted to connect said levers directly, the projecting operating-handle, and contact-springs connected to the local working-circuit and having their free ends projected into the path of the levers, so that the ends of the latter will make rubbing contact with said springs.

8. The combination, with the plate F, carrying the contact-levers, springs, and operating-levers, and having a lateral extension, i, through which the connecting-wires and operating-lever pass, of the cover B, open at its bottom, as and for the purpose described.

9. The combination, with the two pivoted elbowlevers, the two contactsprings arranged opposite the ends of the levers, so that the ends of the latter may form contacts rubbing upon the springs, and the intermediate caniplate, X, adapted to move the levers apart, so as to break the workingcircuit formed by the levers and springs and at the same time to form a direct connection between the levers.

Signed at Lynn, in the county of Essex, State of Massachusetts, this 24th day of November, 1883.

ELIHU THOMSON.

E. WILBUR RICE.

Witnesses: \V. O. WAKEFIELD, E. B. Donn. 

